This 'feature' was introduced in 4.1.2. Maybe not the best time to do so in a maintenance release.

Also, I recommend finding a prominent place to document the fact that it is not possible to use namespaces/class names with 'appname.app'.

It is not really obvious what is happening when it happens.

EDIT:
Maybe a good way around the documentation problem is to throw an exception when assigning the application object to a property that is not empty - and include a reference to how to reconfigure the application.